Licanic acid resin and process of making



s PATENT orrlcs I LICANIC ACID RESIN AND PROCESS OF MAKING Alfred E.Bheineck and mammnabm, Louisville, 1a., assiznors to Devoe & Baynolds00.,

Inc., a corporation of New York No Drawing. I Application December 30,1938,

Serial No. 248,514

8 Claims.

This invention relates to resinous licanic acid compositions and moreparticularly to the resin obtained by decomposition of 1 licanic acid,and modified products of such resin. This applica- 5 tion is acontinuation in part of our application Serial No. 70,612 filed March'24, 1936, and contains subject matter derived from our applicationSerial No. 63,862 filed February 14, 1936.

The resin composition of this invention may 10 be prepared -from licanicacid itself or from a mixture of licanic acid with the other fatty acidsthat occur in oiticica oil and poyoak oil. The production of the resinis obtained by decomposing the licanic acid by proper heat treatment of15 that acid or fatty acid mixtures containing licanic acidunder-conditions that facilitate the splitting-01f the elements of waterfrom the licanic acid molecule with progressive decomposition of theacid into a resin. This resin is useful. in

20 coating compositions and serves especially as a substitute forshellac. This resin may be modified by treatment with maleic anhydrideand the resulting product may be esterified to produce valuable modifiedproducts of the licanic acid resin;

25 bond structure has been retained although the acid has beendecomposed.

Prior workers in the fatty acids field have proposed thickening, bodyingor gelling of the fatty acids of various drying and semi-drying oil's,the sole purpose being to produce an improved stand oil. The product isa viscous liquid oil having substantial body but definitely is not aresin and doesnot possess the solidity, hardness, and frac- 35 turecharacteristics that distinguish the resins from the bodied oils.

In the prior processes the oils or fatty acids thereof are subjected totreating conditions con:- ducive to increasing the body or viscosity ofthe 40 oil but in all cases the treatingconditions are controlled toprevent decomposition of the oil. Therefore, the fatty acids do notdecompose but simply polymerize and thereby efiect an increase inviscosity. In a typical process the oil or fatty 45 acids are distilledto remove the unpolymerlzable constituents and the distillation iscarried out in the presence of a non-oxidizing gas such as for exampleunder an atmosphere of carbon dioxide. The still residue is a thickenedliquid 50 known as stand oil.- It has no fracture characteristic, it isnot a solid at room temperatures and P ysical or does not possess any ofthe other chemical characteristics of the resins.

' Our present invention is based upon the dis-' 55 covery that licanicacid when treated under proper decomposing "conditions will decomposeinto a'resinous product that is a solid at normai,*atmospherictemperatures and has a fracture and hardness cha'racteristic thatdefinitely o identifies itas a resin.. -Am0n g the numerous which isevidence that the conjugated double fatty acids of drying andsemi-drying oils, we have found by our exhaustive tests that the fattyacids of only two of these oils are suitable as starting materials forthe production of our new resin, and they are the fatty acids ofoiticica oil and poyoak oil. It appears that both of these oils containlicanic acid or a like acid having a ketone group in'the fatty acidmolecule; This licanic or ketone group acid may be isolated from theother fatty acids in the oiticica or poyoak oil before beingdecomposedint'o the desired resin product; or a mixture of thisacid withthe other associated acids in oiticica or poyoak oil may be used in ourprocess, but it is only the ketone type acid that decomposes andresinifies.

The resin obtained by decomposition of the licanic acid alone is harderand accordingly more desirable for a number of uses than the resinobtained by decomposition of the mixture of I icanic acid with the otherfatty acids in oiticica and poyoak oils. The resinified product derivedfrom the mixed acids is somewhat softer and more wax-like because of thepresence of nonresinifying components.

Our numerous tests show that with the exception of the oiticica andpoyoak oil acids, the fatty acids of the drying and semi-drying oils donot resinify upon heating and therefore do not form the resin productsof our invention. The characterizing constituent of the oiticica andpoyoak oils, namely the licanic acid with a ketone group, is anessential to our decomposition and resinifying process in which water isproduced by combination of certain of the hydrogen and oxygen atomsinthe acid molecule. When the water is split-off a rearrangement of themolecule takes place which is totally diiferent from the ordinarydehydration of a fatty acid. This decomposition reaction, which forms aresin, may be illustrated empirically as follows: a

lustrated by the above formulas is the result of an actual decompositionwith evolution of water from the licanic acid molecule. We believe itlikely that the ketone group undergoes a condensation with the carboxylgroup of the acid as of water. Thus, if licanic acid is heated in anopen vessel, it begins to lose water at about 200 C. and eventuallydecreases in acid'value and becomes very viscous, approaching a solidstate or substantially resinifying. The speed with which thisdecomposition takes place is dependent upon the temperature. Thus whilethe effect begins at about 200 C. it is much more apparent attemperatures somewhat higher than this and, for direct heating,temperatures of between 240 C. and 300 C. and preferably between about240 C. and 270 C. can be used. The top limit given is merely a practicalone 'and is not critical to the reaction, the actual limit being atemperature at which the acid is materially darkened or otherwiseinjured.

The direct heating may take place either in vacuum (such as a vacuum ofbetween about 1 mm. and 4 mm. of mercury) or in an open kettle andpreferably is accompanied by entle agitation to facilitate removal ofthe water.

A preferred method of accomplishing the decomposition reaction is bydissolving the licanic acid in a solvent having a boiling point somewhatabove 200 C. and then boiling the mixture under such conditions that thesolvent is refluxed back to the boiling mass after separation of theevolved water. Under these solvent conditions, decomposition of theresin is facilitated. In such case a somewhat lower temperature issuflicient, as for example, temperatures in the order of about 225 C. to275 0., though higher temperatures may also be used in this connection.

'usually soluble in mineral spirits or other petro- Various organicsolvents of types now on the market are available about the onlyrequire= ment being that the solvent shall be substantially inert to theacid and so have a boiling range between about 200 C. and 300 C. Aproduct which has been found excellent for this purpose is a product nowon the market and widely known under the name of Hydrosolvent #4-ahydrocarbon which has a. boiling range of between about 215 C. and 238C.

When licanic acid is thus heated under decomposing conditions'untilthe'evolution of water has ceased, it will be found that the acid haschanged in many respects. Its acid number is greatly reduced (e. g. inone case from 175 to about 101) and on cooling it will set to a solidmass with a characteristic fracture and pleasant odor. This resinousmass is thermoplastic, being readily' softened with heat, is soluble atnormal temperatures in the usual ketone, ester, aromatic hydrocarbonsolvents and in blown oils, such as blown linseed oil, but issubstantially insoluble in cold 7 aliphatic hydrocarbons and raw oils.Thus it is clearly distinguishable from the viscous products whichresult from heating the usual drying oil and semi-drying oil fattyacids. The latter are leum hydrocarbons.

The invention may be readily understood from the following example:

Oiticica oil fatty acids were separated from the oiticica oil by one ofthe methods commonly known in the art. The separated fatty acids weredissolved in a 50% solution in an aliphatic hydrocarbon solvent having aboiling range between 50 C. and C. (e. g.'hexane). The solution was thenchilled down to a temperature of about 0 C. which caused the materialwhich is here called licanic acid to separate out as a wax-like whitesolid. It was found that this acid was very susceptible to atmosphericoxidation so that either the separated acid or even the mixed raw acidswere dlfllcult to store. The acids prepared by saponiflcation of the oilwith alkali are usually light in color and when used promptly afterpreparation yield a light colored product, whereas the acids which areavailable commercially are longer was being condensed in the refluxapparatus. This usually requires about three hours.

It was found that about 100 parts of acid having an acid number of 176evolved about 5.4 parts of water. Thisis simply an observation made andis not intended in any way as a limitation, as

experience may show that this figure is subject to substantialmodification.

After the evolution of water was completed, the solution was allowed tocool downand the'resin was more completely precipitated by adding anexcess of methanol. After removal of the solvent this resin product hadan acid number of 93, was a hard solid at room temperatures and had afracture characteristic of the resins.

Further modification of the licanic acid or licanic acid resin may beobtained by treating with maleic anhydride and the reaction productesterifled. These treatments may be carried out in open vessels or in aclosed system with solvents or'combinations thereof. The maleicanhydride reaction may be effected by treatment of the licanic acideither before or after its decomposition into a resin. Whichever prop-lcedure is used the-resulting product may then be esterified withgiycerine or glycerides. If the treatment is carried out beforedecomposition, that is, upon the normal licanic acid, the resultingproduct is then subjected to decomposition and resinification in amanner similar to that described 'hereinabove. Inaccordance with oneillustrative embodiment the licanic acid may be dissolved in analiphatic hydrocarbon, then the maleic anhydride added and the solutionheated until considerable frothing takes place which indicates thereaction between the licanic acid and the maleic anhydride. Theresulting product may then be heated, substantially as above described,under vacuum to effect resiniiication. The product so prepared is asolid atroom temperature and in one instance possessed an acid value ofabout 204 as compared with an acid value of 272 of the addition productof licanic acid and maleic anhydride prior to resiniflcation.

The product resulting from esterifying with glycerol the resinifledlicanic acid-maleic anhydride reaction product (whether the reactionwith the maleic anhydride is conducted before or after resiniflcation ofthe-licanic acid) is a resinous body which is definitely a solid atnormal room temperature so that it has a characteristic fracture, and inthis regard it definitely distinguishes from the usual product obtainedby the reaction of maleic anhydrlde and a drying oil. which is 20 ingvigorously at about 225 C. until water no I characteristically soft orbalsam-like. It should be noted that the resinificatio'n of the licanicacid is a distinct step from tl iesterification, and this resiniflcationcan take place only prior to esterification, though/such resinificationmay take place either before or after the maleic anhydride addition. Inother words, the resinified glyceride of this invention cannot beproduced by any steps aimed to accomplish resiniflcation afteresteriflcation.

. It is to be understood that the foregoing examples are given onlybyway of illustration and ill] may be modified and changed in manyparticulars without departing from the spirit of our invention.

What we claim is:

l. A resinous body consisting essentially of the product resulting fromdecomposing licanic acid by heating said acid to between about 200 C.and 300? C.-until the evolution of water substantial: ly ceases andthe'acid is decomposed into a resin.

2. A resin product normally solid at atmospheric temperatures and havinga definite resin fracture characteristic, comprising .a residue of heattreated fatty acids containing decomposed and resinified licanic acid,said fatty acids being those acids which occur in drying oils of thegroup consisting of oiticica and poyoak oils.

3. A process of preparing resinous licanic acid comprising decomposinglicanic acid by heating said acid under decomposing conditions and withthe evolution of a resinous product, which is solid at atmospherictemperatures and which has a definite fracture characteristic of resins,is produced.

4. A process for preparing a resin product as defined in claim 3 inwhichthe licanic acid is mixed with the other fatty acids normallyoccurring in a drying oil selected from the group consisting of oiticicaoil and poyoalr oil.

5. A process of preparing licanic acid resin comprising decomposinglicanic acid by dissolving said acid in an organic solvent having aboiling point of at leastabout 200 C. and heating the licanic acidsolution so as to continuously distill .oil the solvent and water untilfurther evolufracture characteristic comprising -decomposed resinifiedketone group fatty acid of oiticica oil.

ALFRED E. RHEDIECK. BENJAMIN RABBI.

